The invention proceeds from a pump unit.
DE 10 2010 040 758 A1 has already disclosed a pump unit, having a drive shaft and the rotatably arranged rotor which is driven by the drive shaft, the drive shaft having, on an end side, an oblique sliding face which causes the rotor with its rotor axis to tumble about a drive axis of the drive shaft, the drive shaft having a first bearing section which faces the rotor and a second bearing section which faces away from the rotor. The first bearing section of the drive shaft is arranged in a first plain bearing and the second bearing section is arranged in a second plain bearing. During operation of the pump unit, greater forces act on the first plain bearing than on the second plain bearing, since the hydraulic pressure forces which occur in the working chambers of the pump unit act on the drive shaft via the rotor and the oblique sliding face and in the process have to be absorbed predominantly by the first plain bearing. However, the load-bearing capability of the plain bearing which faces the rotor is limited up to a predefined working pressure in the pump unit.